1. Field of Invention
Embodiments of the present invention relate generally to an insertion device used commonly for subcutaneously puncturing a site in a patient to insert a soft cannula that forms part of an infusion set for subcutaneous delivery of a fluid, drug or other infusant by means of an external infusion system. More particularly, embodiments of the invention relate to an insertion device capable of being disposed of without the risks of causing unintended harmful injuries to persons.
2. Description of Related Art
Insertion devices are generally used in the field of subcutaneous infusion sets. These infusion sets are used for delivering a fluid, medication or other infusant, for example, insulin, to a subcutaneous site in a patient. Such an infusion set is described, for example, in U.S. Pat. Nos. 6,520,938 and 6,056,718, which are herein incorporated by reference. Another example is described in co-pending U.S. application Ser. No. 11/003225, entitled Medication Infusion Set, filed on Dec. 3, 2004, which is herein incorporated by reference. These devices commonly include a delivery tube connected to an infusion pump or other fluid or medication delivering device. Such an infusion set may include a base portion with a cannula deposited in the skin of a patient, and an adhesive patch at the base of the cannula housing to hold the cannula in place. The cannula is inserted into the skin of a patient, with the aid of an insertion device, to facilitate the subcutaneous transfer of an infusant. The possibility of disconnecting the infusion set from other parts of the infusion system is provided in order to improve the user comfort.
The use of a cannula further improves patient comfort. The cannula is generally more flexible than a rigid needle and allows the user to perform activities with much less pain or discomfort. While this allows for increased mobility, there remain disadvantages to patients for other reasons. To insert the cannula in place, an insertion device, commonly including a needle, is used and then discarded after attaching the cannula to the infusion site. Therefore, upon withdrawal of an insertion device from the base, there are potential risks of unintended harm from the sharp end to the user or others.
Because of the risk of harm during or after disposal of the insertion device, it is helpful if the insertion device can be quickly and securely covered. And because each insertion device may travel to numerous locations during the disposal process, and be handled by many different people, it is advantageous if the coverage withstands the entire process and remains secured after it reaches its final disposal location. Therefore, it would be useful to provide an insertion device with a way in which the needle can be covered quickly and securely after use and the insertion device discarded without the danger of causing unintended harmful injuries to persons.
While some insertion devices in the art provide ways to cover the exposed needle, there are disadvantages. In general, known insertion devices involve separate pieces that require the user to fit the pieces together. The cumbersome assembling process takes additional time and space. Moreover, the assembling process itself presents additional dangers of suffering needle pricks. Other known insertion devices, while not requiring assembly of separate pieces, involve complicated maneuvering to cover and secure the needle. A known insertion device is described in U.S. Pat. No. 6,355,021. The insertion device comprises a needle and hub. The hub includes a pivotable shield that can be manipulated to cover the needle as well as interlock the entire insertion device.